JP4132959B2 - Protective device - Google Patents

Abstract

A first machine part (10) performs working movements against a second machine part (11). A photoelectric barrier (PB) (20) can be positioned between these two parts and on one (10) of them in such a way that its light beam (23) has a safety gap from this machine part (10). This gap can be adjusted by safety devices (15-18) supporting the PB. If the light beam is broken, a blocking device stops machine working movement.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a protective device for a machine in which the first machine part is moved against the second machine part.
[0002]
[Prior art]
This protective device is provided with at least one photoelectric detector in which the light beam extends perpendicularly to the working operation direction, and this photoelectric detector is specifically a laser photoelectric detector. The photoelectric detector is arranged on one of the two machine parts so that the light beam can be kept at a safe distance from the machine part. This safety distance is set by protective means that are adjustably arranged on one machine part. The protection means includes at least one photoelectric detector, stop means for stopping the work operation when the light beam is interrupted, and switch-off means for switching off the stop means directly before the light beam is interrupted. .
[0003]
In the case of such a protective device disclosed in German Patent Publication No. 19717299A, it is possible to arrange two photoelectric detectors, ie two light beams in succession in the direction of operation, and to adjust the safety distance between them. it can. In setting the distance, the safeguard is moved towards the one mechanical part with the protective means until the initial beam is blocked by the machine part or the tool to set the safe distance. However, in this arrangement, it is necessary to arrange two photoelectric detectors or light beams continuously in the operation direction, which increases the cost.
[0004]
A single photoelectric detector can be used to place a block (shim) to manually set the distance from one machine part or tool and move the beam until it is blocked by the block. As is known, this adjustment, in the case of a very large machine, requires two people and puts the person holding the padding at risk of injury from the tool.
[0005]
[Problems to be solved by the invention]
The object of the present invention is to provide a protective device of the type mentioned at the outset, which does not require an auxiliary adjustment photoelectric detector and can set the safe distance of the protective means by a single operator or completely automatically. Is to provide.
[0006]
[Means for Solving the Problems and Effects of the Invention]
According to the invention, this object is to carry out the first action of the protection means until the light beam is interrupted by the mechanical part to which the photoelectric detector is mounted , and the second action of the protection means in the opposite direction. This is achieved by providing means. Moving distance in a second operation for setting the safety distance can be predetermined by the control means.
[0007]
Distance According to an advantageous embodiment of the present invention, safety distance, since it is stored in the control means as the distance of the second operation, in order to set the safety distances electrically storing a photoelectric detector Simply move based on the. The second adjustment photoelectric detector is not necessary, leading to significant cost reduction. By setting different stored values in advance or using calculated stored values, it is also possible to set the safety distance in different ways according to the respective requirements.
[0008]
The claimed method represents an advantageous development and improvement of the protection device according to the invention.
In order to store an operation for setting or predetermining the safety distance, the control means preferably comprises a data memory. In order to use this data to maximize it is advantageous to provide means for detect the overrun displacement of the machine parts to be moved after the stop signal. Thereby, a safe distance in the data memory can be determined in advance using a value related to the overrun displacement . The safety distance may be set in an optimal manner based on the settings of the employed tool or machine and other parameters such as service life, drive and brake device conditions, and the like.
[0009]
In order to detect a change in state, it is advantageous to provide a comparison means for comparing the stored overrun displacement with the newly detected overrun displacement . This means resets a new safety distance based on the new overrun displacement when a predictable opening is detected between the old overrun displacement and the new overrun displacement . Means for detect the overrun displacement upon approaching operation of the machine part is preferably activated after or a predetermined number of cycles after the power supply is cut off.
[0010]
To increase safety, some electrical control switch or may be provided a radio control elements, which are functionally connected to the protective means for moving. There may also be provided means for activating the approaching action of the machine part only when a preselected electrical control switch or radio control element is reached. This means comprises an auxiliary safety means to avoid setting too short safety distance when there is an error in setting the safety distance.
[0011]
When setting the safety distance, it is advantageous to provide an electric motor drive for moving the protective means manually or completely automatically.
To increase the accuracy of adjustment, the control means comprises means for setting the distance of the second operation only when the light beam is interrupted. This means is provided for activating the approaching action of the machine part only when the machine part reaches a preselected electrical control switch or radio control element.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
BRIEF DESCRIPTION OF THE DRAWINGS Advantageous developments and advantageous forms of the invention are illustrated by the following description of an embodiment with reference to the drawings.
The bending press shown in FIGS. 1 and 2 usually comprises an upper machine part 8 with a top tool 10, which is movable towards a fixed lower machine part 9 with a bottom tool 11. is there. The work movement direction A is indicated by a bidirectional arrow. In an alternative design, it is of course possible that the top tool 10 is fixed and the bottom tool 11 moves. The elongated top tool 10 has a working part 12 with a wedge-shaped cross section, while the bottom tool 11 has a corresponding wedge-shaped groove 13. The working unit 12 enters the groove 13 during the working operation, and as a result, is supported by the bottom tool 11 to bend the thin plate 14 or give an angle thereto.
[0013]
The rest of the originally known bending press has been omitted for the sake of clarity. The top tool 10 and the bottom tool 11 may have different lengths and cross-sectional shapes, and the top tool 10 and the bottom tool 11 are detachably attached to the upper machine part 8 and the lower machine part 9, respectively.
[0014]
As protective means, guides 15 and 16 are attached to the narrow side of the top tool 10 facing each other, for example using screws. The guides 15 and 16 allow the holders 17 and 18 of the three photoelectric detectors 20-22 to move in the vertical direction of setting or adjustment. The direction of this adjustment is indicated by a double arrow B and corresponds to the work movement direction A. In order to drive and move the holders 17 and 18 by a motor, a motor drive device such as an electric motor, a linear drive device, and a drive cylinder is provided and interlocked with the guides 15 and 16. Each of the photoelectric detectors 20-22 is provided with a light source as a laser source and an optical receiver such as a laser receiver, for example, in a known manner. The machine is arranged on the other holder 18. In principle, it is also possible to substantially increase the number of light sources by using one beam splitter as a plurality of transmitted beams. Furthermore, it is possible to form two parallel light beams by a parallel laser beam generated by refraction using a reflecting means. In such a design, for example, the light source and the receiver are arranged on one holder 17, and the reflecting means is arranged on the other holder 18.
[0015]
The three photoelectric detectors 20-22 are all designed as protective photoelectric detectors and extend in a plane perpendicular to the working movement direction A. There is no limit to the number of photoelectric detectors. In the simplest case, only one photoelectric detector may be provided, for example, only the photoelectric detector 20.
[0016]
When any of the light beams from the photoelectric detectors 20-22 is blocked by the protection of the above-described protection means, that is, when the object is moving, the approaching operation of the top tool 10 toward the bottom tool 11 is suddenly performed. Be stopped. Since such a bending press machine is frequently manually operated, there is a great risk that the operator's hand or arm will be crushed or cut into the operating direction. Therefore, the safety distance between the laser beam groups 23 of the photoelectric detector 20-22, specifically, the photoelectric detector 20, must be determined so that, for example, a finger does not enter between them. On the other hand, if the safety distance is too large, when the laser beam group 23 is interrupted, the brake is applied and stopped before reaching the obstacle. Therefore, the safety distance may be between 3 and 10 mm, for example.
[0017]
For example, when it is necessary to increase the safety distance because the overrun displacement or braking distance of the top tool 10 is longer, in the case of the photoelectric detector 20 or of the photoelectric detector 20-22 in a plane away from the top tool. In this case, for example, even if one finger or all the fingers enter between the top tool 10 and this plane, there is a risk that the machine will not be stopped for safety reasons. In such a case, the photoelectric detector is arranged, for example, in an L shape or a T shape so that two or more planes are continuous in the working direction. In this case, the photoelectric detector 20 employed for setting the safety distance is disposed in a space closest to the top tool 10.
[0018]
The electronic control means 26 performs the operation control of the upper machine part 8 and the operation control of the holders 17 and 18, and thus the photoelectric detector 20-22 in the adjustment direction B. The measuring module detects the movement of the upper machine part 8, and thus the top tool 10, and takes the form of, for example, an inductive or optical displacement sensor, a linear potentiometer, a sync with a known design, etc.
[0019]
In the safety distance adjustment process, the adjustment drive device measures time in response to a manual or automatic start signal in one direction, or the drive device has a displacement measuring means and corresponds to the set value. The position is implemented by acting as a basis for adjustment. The adjustment of the safety distance starts with the reversal of the adjustment drive or when the effect of the interruption of the laser beam 23 ceases.
[0020]
The adjustment process described with respect to the safety distance can be carried out fully automatically, but in a simple apparatus it can also be carried out by manual control using appropriate electrical control commands transmitted to the adjustment drive.
To increase safety, grid-like electrical control switches or contacts (not shown) on guides 15 and 16 which are activated, i.e. activated respectively, according to mobile holders 17 and 18, or Other radio control elements may be provided. At the end of the adjustment process, at least one special switch must be activated or activated in order to reactivate the rapid approach of the top tool 10 to the bottom tool 11. Therefore, it is possible to prevent a safety distance that is substantially too small from being set due to some inappropriate action.
[0021]
The magnitude of the safety distance substantially depends on the overrun displacement of the top tool 10 after the stop or braking command, that is, the braking distance. This dependency may be taken into account by automatically associating stored settings with measured overrun displacements. For this purpose, there is a need for measuring means for overrun displacements that can be started manually or automatically, depending on specific variables such as time, power reset and the like.
[0022]
If the module 27 is used, the movement of the top tool 10 can be transmitted to the control means 26 from each position, that is, from each position. In order to measure the overrun displacement during the downward approach of the top tool 10, the control means 26 sends a stop command to the drive (not shown) from the top tool 10 or the upper machine part 8, respectively. send. The measurement module 27 detects the first position signal at the time of the braking command and detects the second position signal at the actual stop time of the top tool 10. By forming the difference between the two signals, an overrun displacement is obtained. Adjustment values are generated or derived in a manner dependent on such overrun displacement and stored in the measurement data memory of the control means 26 in order to set a safe distance. The safety distance should be at least equal to the overrun displacement, but preferably should be only slightly larger. The simplest case is derived by associating overrun displacement with a specific multiplication factor.
[0023]
According to another configuration of the invention, the stored adjustment values are checked or examined periodically or when certain events occur. Since the data memory is configured in the form of a non-volatile memory, the adjustment value remains in the memory even after the power supply is cut off. When a new overrun displacement is measured, it can be seen by comparison that the new overrun displacement is significantly different from the previous measured overrun displacement. The adjustment value is set in an appropriate manner and will replace the previously stored adjustment value. Then, until the new adjustment process or work is automatically performed, the approaching operation of the top tool 10, that is, the work operation of the entire machine is hindered, and a new safety distance is set based on the new adjustment value by this process. .
[0024]
In order to ensure that the interruption of the laser beam 23 by a workpiece, for example a sheet metal, does not cause a stop action of the top tool 10 which would not be desired first, a switch not shown When a certain distance from the workpiece or from the bottom tool 11 is reached, which is substantially equal to a safe distance, the operation of the photoelectric detectors 20 to 22 is stopped by the switch-off means. This stopping means can be controlled by, for example, a position sensor, a distance measuring element, or the like.
[0025]
FIG. 2 shows that the thin metal plate 14 to be operated is pulled out at that position or has an opening, and a finger 25 of an operator (not shown) is inserted into the groove from the upper surface side of the bottom tool 11. Or the case where it entered in the recessed part 13 is shown. In this case, the single photoelectric detector 20 provided near the working end of the top tool 10 will not prevent injury. For this reason, in the embodiment of the present invention, a plurality of photoelectric detectors 20 to 22 are provided side by side on one plane.
[0026]
Aforementioned protector is of course the bending is not limited to the press machine and cutting machine, two for machine part performs the approach operation towards one another, every situation, such as body parts entering between them injured Can be used. In addition, a switch-off circuit for safety reasons will necessarily protect the machine or machine part if the object interferes with the movement so as to damage the machine part or tool.
[0027]
The protective device according to the present invention may be used for, for example, a punching machine, a hinged door, a hatch cover, a planer, a sliding door, and the like.
[Brief description of the drawings]
FIG. 1 is a vertical side view of a bending press equipped with a protective device.
FIG. 2 is a side view of the bending press shown in FIG. 1, with the top tool lowered.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 8 ... Upper machine part 9 ... Lower machine part 10 ... Top tool 11 ... Bottom tool 20, 21, 22 ... Photoelectric detector 26 ... Electronic control means 27 ... Measurement module

Claims (9)

A protective device for a machine in which the upper machine part moves relative to the lower machine part,
And at least one photoelectric detector, mounted on said machine part component, has a direction of movement and vertically extending beams of the upper machine part, wherein the light rays away only safe distance from the upper machine part Positioned between two machine parts, the safety distance can be set by protective means supporting the at least one photoelectric detector, which is adjustably arranged on the upper machine part. A photoelectric detector;
Stop means adapted to brake the upper machine part when the light beam is interrupted;
A switch-off means for switching off the stop means when the distance between the upper machine part and the lower machine part reaches a certain distance ;
Performs a first operation of the protective means in the direction toward the upper machine part side to the light beam by the previous SL on mechanical parts is blocked, also it means for performing a second operation of the protective means in the opposite direction,
Control means for adjusting the safety distance during the second operation, including a data memory for storing an overrun displacement that predetermines the safety distance;
Means for detecting an overrun displacement after a braking signal of the upper machine part;
Comparing means for comparing the overrun displacement stored in the data memory with a newly known overrun displacement;
Means for resetting the safety distance according to the new overrun displacement when a predetermined opening is found between the previous overrun displacement and the new overrun displacement;
Protection device characterized in that it comprises a. Characterized in that it comprises means for detecting the overrun displacement during an approaching action of the upper machine part to the lower machine part after a power supply has been interrupted or after a predetermined number of cycles, The protection device according to claim 1. A plurality of electrical control switches or radio control elements connected to the protection means;
At the end of the safety distance adjustment step, the approach of the upper machine part to the lower machine part is reactivated by the plurality of electrical control switches or the wireless control element. Item 3. The protective device according to Item 1 or 2. A protective device for a machine in which the lower machine part moves relative to the upper machine part,
At least one photoelectric detector having a light beam attached to the upper machine part and extending perpendicular to a direction of movement of the lower machine part, the light beam being separated from the upper machine part by a safe distance; The safety distance is set between two machine parts, and the safety distance can be set by means of a protective means supporting the at least one photoelectric detector, which is adjustably arranged on the upper machine part. A detector;
Stop means adapted to brake the lower machine part when the light beam is interrupted;
A switch-off means for switching off the stop means when the distance between the lower machine part and the upper machine part reaches a certain distance;
Means for performing a first action of the protection means in a direction toward the upper machine part until the light beam is blocked by the upper machine part, and a second action of the protection means in a reverse direction;
Control means for adjusting the safety distance during the second operation, including a data memory for storing an overrun displacement that predetermines the safety distance;
Means for detecting an overrun displacement after a braking signal of the lower machine part;
Comparing means for comparing the overrun displacement stored in the data memory with the newly found overrun displacement;
Means for resetting the safety distance in response to the new overrun displacement when a predetermined opening is found between the previous overrun displacement and the new overrun displacement;
A protective device comprising: Characterized in that it comprises means for detecting the overrun displacement during an approaching action of the lower machine part to the upper machine part after a power supply has been interrupted or after a predetermined number of cycles, The protective device according to claim 4. A plurality of electrical control switches or radio control elements connected to the protection means;
The approach of the lower machine part to the upper machine part is reactivated by the plurality of electrical control switches or the wireless control element at the end of the safety distance adjustment step. Item 6. The protective device according to Item 4 or 5.   The protection device according to any one of claims 1 to 6, further comprising a motor drive device that starts the operation of the protection means manually or executes it in a fully automatic manner.   8. The control device according to claim 1, further comprising means for starting adjustment of the safety distance during the second operation only when the light beam is blocked. Protection device. At least two photoelectric detectors are arranged in two planes arranged in order in the direction of the approaching operation, and the photoelectric detector provided for adjusting the safety distance is closer to the upper machine part. The protection device according to claim 1, wherein the protection device is disposed on the plane.

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